中国31个省份18岁以下新型冠状病毒本土感染者的流行特征分析

Epidemiological characteristics of indigenous 2019-nCoV infection in population under 18 years old in China

目的描述我国31个省份<18岁新型冠状病毒(新冠病毒)本土感染者的流行特征,为优化新冠病毒感染疫情防控措施提供参考。方法研究对象为2020年4月29日至2022年5月31日,中国传染病信息报告管理系统中所有年龄<18岁的新冠病毒本土感染者。对感染者的时间、地区、人群分布、临床严重程度以及确诊病例发病至确诊时间间隔进行分析,并分析不同流行阶段感染者的流行特征。结果研究期间,我国共报告63916例<18岁新冠病毒本土感染者;其中,确诊病例14777例(23.12%),无症状感染者49139例(76.88%)。月报告感染者数在2022年4月达到高峰,为40864例。感染者分布在30个省份的187个地级及以上城市,其中,上海市(41562例)、长春市(5753例)和吉林市(3888例)占全国报告总数的80.11%(51203/63916)。男性占54.34%;感染者年龄M(Q_(1),Q_(3))为10(5,14)岁,57.73%的感染者集中在6~15岁;职业分布以学生为主(56.14%)。确诊病例的发病至确诊时间M(Q_(1),Q_(3))为1(0,2)d。报告无症状感染占76.88%,轻型占21.78%,普通型和重型分别占1.32%和0.02%,无危重型和死亡病例;<1岁年龄组的重型/危重型占比(0.12%)高于其他年龄组。在不同流行阶段中,以Omicron变异株流行为主阶段的无症状感染占比最高(78.43%)。结论我国31个省份<18岁本土感染者主要为6~15岁中小学生,以无症状感染和轻型为主,临床严重程度较低;仍需加强对低年龄组感染者的监测,强化学龄儿童的疫情防控。

Objective To analyze the epidemiological characteristics of indigenous 2019-nCoV infection in population under 18 years old in 31 provinces of China,and provide evidence for the prevention and control of COVID-19.Method Demographic and epidemiologic information of children and adolescents with 2019-nCoV infection reported in China between April 29,2020 and May 31,2022 were collected from China's Disease Prevention and Control Information System.We analyzed the epidemiological characteristics of the 2019-nCoV infection in children and adolescents and compared the epidemiological characteristics of the cases at different epidemic stages.Result A total of 63916 indigenous 2019-nCoV infection cases in children and adolescents were reported in China from April 29,2020 to May 31,2022,in which 14777(23.12%)were confirmed cases and 49139(76.88%)were asymptomatic cases.An obvious incidence peak(40864 cases)was observed in April,2022,and two sub-peaks were observed in January,2020 and January,2021,respectively.The 2019-nCoV infection cases occurred in 187 cities above prefecture level in 30 provinces,the cases reported in Shanghai(41562 cases),Changchun(5753 cases)and Jilin(3888 cases)accounted for 80.11%of the total cases(51203/63916).The proportion of the cases in males was 54.34%.The age of the cases,M(Q_(1),Q_(3))was 10(5,14)years,and 57.73%of the cases were 6-15 years old.The cases in students accounted for the highest proportion(56.14%).The interval between illness onset and diagnosis of confirmed cases,M(Q_(1),Q_(3))was 1(0,2)days.Among the 2019-nCoV infection cases in children and adolescents,76.88%were asymptomatic,21.78%were mild ones,1.32%were moderately severe ones,0.02%were severe ones,and there were no critical cases and deaths.Compared with other age groups,the proportion of severe or critical cases was higher in children aged<1 year(0.12%).The proportion of asymptomatic infections was highest in Omicron variant epidemic(78.43%).Conclusion The 2019-nCoV infection cases in children and adolescents aged<18 years in 31 provinces in China were mainly primary and secondary school students aged 6-15 years.Most cases were asymptomatic and mild ones with low clinical severity.It is still necessary to strengthen the surveillance for 2019-nCoV infection in children and adolescents to improve the prevention and control of COVID-19 in school age children.